Home AppliancesDishwasher

How To Make Dishwasher Drain Hose Connections

Plumber Connected The Dishwasher In The New Kitchen

Connecting the dishwasher hose is a strenuous activity, especially if you do not know how it works. However, you will find it as easy as pie when studying it in detail.


Making dishwasher drain hose connections might seem like a very difficult task. However, it can be very simple and easy with the right knowledge and techniques. There are four ways you can make dishwasher drain hose connections:

  • Through an air gap to garbage disposal
  • Through an airgap directed to the drain
  • In a high loop to garbage disposal
  • In a high loop directed to the drain

Making drain hose connections is an easy DIY task. However, you can seek professional assistance if it appears to be a daunting task.

This article will elaborate on 4 different ways to make dishwasher drain hose connections. You can follow the exact steps to make the perfect drain connections without having to pay any technician for them.

Understanding Before Making Connections

When replacing the dishwasher drain with a new one, the process becomes a lot easier as you can simply remove one connection and attach it to a similar other connection.

However, if you are doing it the first time for your new dishwasher, you might also need some additional guidance and equipment.

Depending on the different variations, you will have four options when considering a drain hose connection.

  • Air Gap Fitting Methods:
    • The drain line can be connected to the garbage disposal via an air gap.
    • The drain line can be connected directly to the sink drain via an air gap.
  • High Loop Installation Methods:
    • The drain line can be set up in a “high loop” configuration leading to the garbage disposal.
    • The drain line can be set up in a “high loop” configuration leading directly to the drain.

Before selecting the right method for you, you have to understand what is the difference between air gap fitting and high loop installation.

Air Gap Fitting

Close-Up Of Male Plumber Fixing White Sink Pipe With Adjustable Wrench

In air gap fitting, a special device is fitted in the sink. Through the air gap fitting, the dishwasher’s pipe takes the water directly to the hose.

This device is a safety measure as it prevents the backflow of dirty drainage water into the dishwasher.

High Loop Installation

Plastic Corrugated Pipe. Construction Background Black Tube

In high loop installation, instead of using the air gap fitting, the drainage line is given a loop up just beneath the sink base. The point of the loop is kept above the sink base cabinet.

The purpose of this method is, again, to avoid the backflow of the drained water.

Garbage Disposal

Build-In Dishwasher With Opened Door In A White Kitchen

Not all dishwashers have a separate garbage disposal unit installed in them. Some have a simple metal filter attached inside the dishwasher over the opening of the drainage hose.

You can first check if your dishwasher has a garbage disposal unit or not. This will help you choose which option to choose when making dishwasher drain hose connections.

4 Ways To Make Dishwasher Drain Connections

Once you have identified which method works for you, you can follow the steps mentioned below to connect successfully to the dishwasher drain.

At first, you will need to gather the tools required to complete the proper steps. Besides the dishwasher drain hose, you will need a hose clamp, a utility knife, and screwdrivers.

Optional materials for various methods include a Y-branch drain tailpiece, a garbage disposal drain adapter, and a pipe strapping/clamp.

Before starting any of the 4 methods, turn off the water connection and unplug the garbage disposal, if any.

1. Making Drain Connections Using Air Gap (With Garbage Disposal)

Installation Hoses For Dishwasher Machine Domestic Connection Plumbing Pipes In Kitchen

When using the air gap to make dishwasher connections, you will find two different drain hoses. The one with a smaller diameter is connected to the drainage pipe.

The other one, with a slightly larger diameter, leads to the garbage disposal unit.

  • Connect the Smaller Hose to Air Gap – Use a utility knife and cut the drain hose pipe to a suitable size. Make sure it is long enough to reach the smaller hose of the Y-shaped tailpiece. Now, fix the end of the drainage pipe to the drain hose and tighten it using a hose clamp.
  • Connect the Larger Hose to Air Gap – For the larger hose pipeline, you will connect one end to the garbage disposal and the other to the air gap. Do not forget to secure both ends with hose clamps.

Make sure there are no twists or bends in the drainage hose pipeline. Always cut the hose to a minimal length when making connections. Kinks or bends can cause blockage over time, thus hindering the proper flow of drain water in the hose.

2. Making Drain Connections Using Air Gap (Without Garbage Disposal)

Installation Hoses For Dishwasher Machine Domestic Connection Plumbing Pipes In Kitchen

If your dishwasher has no separate garbage disposal unit, you must connect the drainage pipe to the sink drainage via the air gap.

  • Connect Smaller Hose to Air Gap – First, you will need to connect the dishwasher’s drainage hose to the smaller tailpiece of the air gap. Ensure the pipe is fitted perfectly to the air gap and secure with hose clamps.
  • Connect Larger Hose to Drainage Pipe – Since there is no garbage disposal, you will need to fix the larger tailpiece of the air gap directly to the drainage pipe of the sink. Again, tighten up the hose joints using clamps. Also, cut the hose to a perfect size before its installation to avoid kinks and bends.

3. Making Drain Connections Using High Loop (With Garbage Disposal)

Installation Hoses For Dishwasher Machine Domestic Connection Plumbing Pipes In Kitchen

If you have no air gap available, the high loop method can be used to make drain connections. Make sure you have gone through the building guidelines when doing so.

Because of poor drainage, most local building owners do not allow using the high loop method.

  • Prepare the Loop of Drain Hose – Since you are making a loop in the drain line, you will need a larger pipe to make the drain connection. Fix the dishwasher drainage pipe using a clamp beneath the sink as much high as possible in a loop shape.
  • Connect the Hose – One end of the drainage tube is larger in diameter than the other. The smaller end is attached to the drainage hose. The larger end of the drainage tube will be connected directly to the garbage disposal unit.

4. Making Drain Connections Using High Loop (Without Garbage Disposal)

Worker Plumber In Installation Of New Dishwasher Machine In Kitchen

If the garbage disposal is absent in your dishwasher and you are not using the air gap, you can work with this method. Follow the steps to make successful drain hose connections:

  • Prepare the Loop of the Drain Hose – To make a loop in the drain line, pull the pipe as much as possible. Now, fix the drain line at the highest point under the sink. This will prevent the backflow of water from the drain into the dishwasher.
  • Connect Hose to Sink Drain – Take the end of the dishwasher’s hose line and connect it to the Y-branch tailpiece. Do not forget to secure it tightly with a hose clamp.
Make the Right Purchase!

Take the measurements of your drain hose pipeline before purchasing the Y-branch tail. Make sure it is of the same size. Otherwise, it will be too tight or too loose to be fixed together.


Connecting a dishwasher drain hose feels like a formidable assignment. However, having the right knowledge and using the right tools can make this challenging task feel like a no-brainer.

The procedure can vary depending on whether your dishwasher has a separate garbage disposal. Moreover, you can use an air gap to make connections or choose a high loop as another option.

In some areas, the use of an air gap is necessary whenever fixing a dishwasher drain line. So, you must check if it applies to you or not.

Frequently Asked Questions

Which Tools Are Required When Making Dishwasher Drain Hose Connections?

To make dishwasher drain hose connections, you will need a drain hose, a few hose clamps, a utility knife, and a screwdriver.

Besides these, you will also need Y-branch drain tailpieces or pipe straps, depending on which method you choose for your drain line connections.

How Do I Measure the Distance for the Drain Hose?

Take your drain line pipe to measure the distance from the dishwasher to the drain or garbage disposal unit. Cut the extra pipe using a utility knife.

Leave one or two inches at each end for adjustments later on.

Leave a Comment

Your email address will not be published. Required fields are marked *